Membranes can be used in separation processes where certain species are retained and other species are allowed to pass through the membrane. Some membrane applications include, for example, use in food and beverage, pharmaceutical, medical, automotive, electronic, chemical, biotechnology, and dairy industries.
Membranes having hydrophilic surfaces have been described. Hydrophilic membranes generally have a tendency for less fouling or pore clogging than hydrophobic membranes. Some membranes prepared from hydrophobic materials require a surface pretreatment step before using for filtration of aqueous feed solutions. In other instances, some hydrophilic membranes have been formed from hydrophilic materials lacking mechanical strength.